Self-cleaning blackboard.



I. D. SAIITAKOFF.VF SELF CLEANING BLACKBOARD'.

APPLICATION FILED APR.l I3. 1917. l

Patented May 22,

/////////r///// /fr blackboards whereon that' class of blackboard vwriting is erased JACK D. sAnTAxoEF, or NEW YORK, N. Y.

SELF-CLEANING BLACKBOARD.

Specication of Letters Patent.

Patented May 22, i917..

Appiicafion sied Aprii 13, 1917. serial No. 161,730.

VTo all whom 'it may concern:

Be it known that I, JACK D. SARTAKOFF, a citizen of Russia, residing in the city of New York, borough of Manhattan, county and State of New York, have invented a certain new and useful Self-Cleaning Blackboard, of which the following is a specification. p

This invention is a self-cleaning blackboard, and relates, more particularly, to wherein the writing is received upon an endless'iexible web adapted to be shifted, from time to time, to present unused surfaces to the writer. Blackboards of this general character have long been employed, children in the home, and, like all other chalk is used, they give olf considerable chalk dust during the writing and subsequent cleaning operations, and particularly during the latter, when the generally by a felt pad.

The object of the present invention is to provide an endless web blackboard adapted for general use, e., in school rooms, railway stations, and as bulletin boards, the salient feature of the invention being the automatic cleaning and washing of the blackboard when the web is advanced. A further feature of the invention embodies the incorporation of means for effecting the disposition of the chalk dust removed from the blackboard during the cleaningv operation. f

Features of the invention, f other than those specified, as well as the advantages thereof, will appear from the hereinafter detailed description taken in conjunction with the accompanying drawing.

In the accompanying drawing I have illustrated one practical embodiment of the invention, but the construction therein shown is to be understood as illustrative, only, and not as defining the limits of the invention.

Figure 1 is a vertical section through a blackboard construction embodying the present invention, said-section being taken substantially in the plane of the line 1-'1 of Fig. 2.

Fig. 2 is a section of substantially the upper half of the structure of Fig. 1, taken in the plane of the line 2-2 of Fig. 1.

Fig. 3 is an enlarged detail of a section of particularly for use by and the nursery,

e the arrow [ders the board gray makes the writing .'or other designations.

r:ertain liquid supply means shown in l, and .l n

Fig. i is a section on the line 4 4 o'f Fig. 3. C

Referring to the drawing, designates a casing provided at its front with an opening a. In'the upper and lower portions of the casing, and extending transversely thereof, are rollers yB and C, and within the cas# ing, and immediately anterior of opening a, is a rigid plate D.` An endless flexible web F, upon the surface of which the writing is accomplished, extends about rollers B and C and forward of plate D, direction rollers d and d being provided at the upper and lower kedges of said plate to .obviate wearing of the. web by said edges. The writing upon web E is accomplished through opening a andupon that portion of the web which rests against plate D, said plate serving as a rigid backing to preclude the web Ifrom yielding under the pressure of the chalk.

Oneof 'the trunnions on which the lower roll C is rotatably mounted is provided with a handle or crank f, to allow oftheadvancing of the web, and also'fixed upon said trunnion is a pulley, gear, or sprocket wheel, g, connected by a belt, gear, or sprocket chain, Vg, to a shaft G, positioned rearward of the back reach of web E. Upon shaft G is fixed suitable cleaning means, shown in the drawing as a bristle brush g2. Crank f is adapted to be turned in the direction of to rotate roller C in a clockwise direction, and the gearing or belt connection between said -roller and brush g'2 is such as to reverse the direction of rotation, sb that the brush will turn in a counter-clockwise direction. Thus, as the crank is turned to advance web E, brush or cleaner g2 is actuated to Vscrub or otherwise erase from said web writing or other may have been previously written or otherwise formed upon said web.

It is found in practice that, after a very brief use of a blackboard, it becomes covered with very fine chalk dust, which renrather than black, and

placed upon the face of the web smudgy and untidy. This gray effect cannot be ordinarily removed through the use of a brush or felt wiper, so that it has generally been to time.

the practice, with blackboards of all kinds, to wash them with a wet'sponge from time The present invention, however,

. embodiesmeans for automatically washing in Fig. 2, is best shown in Figs. 3 and 4,

at least a portion 'of the web during each advance movement thereof. shownin section in Fig. l. and inelevatl'on wherein Fig.' 3 is an enlarged section of the showing of Fig. l.

The washing means embodies an elongated tank -or reservoir H, supported by angle-irons h4, longitudinally of which tank extends a shaft z., carrying a plurality of `curved blades la', so shaped as to form pockets. Shaft is geared, belted, or otherwise operatively connected with shaft Gr,- said connection being shown as a belt or sprocket h2, so that,'when shaft G is actuated, shaft I. is simultaneously rotated. Liquid, gener- -ally water, is supplied to reservoir H through a pipe 1J, the iow of liquid through said pipe into the reservoir being controlled by any suitable form of float-valve, `here shown as embodying a valve z" adapted to be closed by a float 2 when the liquid in the reservoir has attained a predetermined height. Any form ofl controlling means, however, may be employed, such, e. g., as the float-valve generally used in conjunction with water-closet Hush tanks, the showing here made-being vmerely for illustrative purposes, only, and not exclusive.

The casing forming reservoirH 1s provided with an outlet spout or mouth 11.3,

which extends, as shown best in Fig. 1,`to-

a position inv intimate relation to the face of web E, so that, when crank 7 is actuated and shaft z. rotated through the connections specified, the pocket plates h will be successively charged with fluid from the reser voir and will deliver said fluid through outlet k3 and directly upon the face of the web. Roller B is preferably made of slightly less diameter than roller C, so that the rear reach of web E against which the liquid is thrown is slightly inclined, whereby lthe liquid will impinge said surfacel and flow downwardly thereover in' a thin film. The

same result of inclining the. rear reach of 1 web E maybe obtained, even if rollers B and C are of the same size, by positioning roller B farther forward of the casing, orl

This means,

flow through a trapped outlet J .i The chalk or lother heavy particles are caught in the trap, which may be cleaned, from time 'te time,'by removi g the 'cleaning cap j provided for this purpose.

After leaving brush g2, .the web is freed of superfluous water by means of a wiper le,

which is yieldably maintained in contactwith said web by any suitabley means,` such as one or more leaf-springs k. Wiper k removes substantially all of the liquid and entralned chalk dust from theweb and Ialso assists in the/ depositing thereof within the base of .the casing. tional wiper or drier L, positioned a little If desired, an addifarther along the path of travel of the web,

may be provided to further free the web o-f molsture. The drier or wiper L, may be .either spring-pressed or manually adjustable by one or more thumb-screws Z, as shown, and is preferably removable to allow ofthe'cleaning thereof when desired.

As web E is-generally madefrom-I some suitable fabric, which is apt to s tretch through continued use, means is preferably provided to allow of the tightening of said web, so that the same may be maintained taut /at all times. vAny desiredform of means for accomplishing this result will )suflice, but I have shown in Fig.` 2 one form as illustrative. The structure there shown conslsts in mounting the trunnions of roller B for vertical sliding movement in slots in the ends o f the casing, and associating with sald trunnlons adjusting screws m, threaded through ,lugs m', projecting laterally fro-m` thewall of the casing. By manipulating the screws m,-roller-B. may be raised or lowered,

as the tension of the web may require. lf

desired, springsmay be positloned between the ends of the adjusting screwsv and the trunnions, or maybe used in lieu of the screws for maintaining the web taut by spring pressure. pressure of the brush or cleaner g2 against the web, said web is backed up at this point by a rotaftable'pressure roll'n, whereby undue strain upon the" web by Qthe brush or cleaner is precluded. i

ln the preferred embodiment of the invention illustrated, casing A is, shownA as formed from sheet metal, and this is the structure preferably employed, although a Moreover, to resist the.

wooden casing may be used if desired. In I an event, it is desirable that a suitable s elf or channel 0 be arranged along the lower edge of opening a, to allow of the ositioning of chalk or other articlesavvit in ready access of the writer. Shelf or channel 0 also catches the chalk dust which falls from the face ofthe blackboard during the writing-operation, s o-that such dust is'not` allowed to fall upon the ioo, andmay be readily removed from the channel, when desired. vCasing A mayvbe mounted in any l suitable way, either by directly securing the will be apparent that .circulate in the surrounding same to a wall, or mounting it upon standards, as occasion may requlre.

It will be apparent from the `foregoing description that the structure is extremely simple, easy to operate,'.and, in its normal operation, washes and cleans theA blackboard every time crank f -is actuated to ad- Vance the web. This is, of course, true when the crank is actuated in a clockwise direction, as hereinbefore explained. It

it would be disadvantageous to allowof the actuation of the crank in a counter-clockwise direction, and, for this reason, suitable means, not shown, is provided to limit the movement of the crank to onel direction only. This means may partake of the form of a/ pawl and ratchet, or any other suitable arrangement, such as is well known and generally adapt.-

Aed to preclude reverse rotation of a moving art. p The casing is substantially dust-proof and, accordingly, the chalk dust and dirt removed from the board during the cleaning and washing operations are not free to atmosphere,

withI the well known, deleterious results'.

All of said dust and dirt is confined within the' casing and is carried 0H and deposited within the trap bythe washing fluid.' If desired, an antiseptic solution may be introduced into the water used during the washing operation, to render the device sanitary in ev'erj,1 respect.`

The foregoing description and showing in the drawing.A deal with the invention in its preferred form. It will be manifest, how- .made, within reasonable limits,

that various l modifications may be in adapt-ing the invention to the various environments of which it is susceptible. It will, therefore, be understood that the showing made is for the purposes of illustration, only, the invention being as broadly novel as is commensu# rate with the appended claims.

' Having thus fully described theinvention, what I claim as new, and desire to secure by Letters'Patent, is:

1.' In a ever,

the movement of the blackboard for automatically cleaning the surface thereof, and.

cleaner,

device of the class der Jribed, a movable blackboard, means operable upon means simultaneously operable to wetA the surface of the blackboardl to be cleaned.

2. In a device ofthe class described, a movable blackboard, means for washing the blackboard, and means for cleaning the same, said washingv and cleaning means being automatically .operable upon the movement of the blackboard.

3. In a device of the class described, the combination of a'movable blackboard, means operable upon the movement of the blackboard for washing the same, and a rotating cleaner also operableupon the movement' of the blackboard for rubbing said blackboard while wet.

4. In a device of the class described, the I combination of an endless web blackboard, means for advancing the blackboard, and

means operable by the-blackboard actuatingmeans for washing and rubbing the blackboard. f

5. In a device of the class described, the

combination of an endless web blackboard,

7: In a device of the class described, a4

movable blackboard, means for imparting movement to said blackboard, and means'for automatically washing said blackboard when the Same is moved.

` 8. In'a device of the lclass described, a blackboard vembodying an endless flexible web, means for advancing the web, and

means actuated by the 'web advancing means for washing a portion of the web during the advancing operation. In testimony whereof I have slgned 4my name to this specification.

' JACKJD. sAnTAKoFF. 

